Devil’s Highway, Crowthorne,
Berkshire
An Archaeological Evaluation
For Bracknell Forest Borough Council
By Danielle Colls
Thames Valley Archaeological Services
Ltd
Site Code DHC06/58
July 2006
Summary
Site name: Devil’s Highway, Crowthorne, Berkshire
Grid reference: SU 8457 6436 to SU 8586 6445
Site activity: Evaluation
Date and duration of project: 31st May – 16th June 2006
Project manager: Steve Ford
Site supervisor: Danielle Colls
Site code: DHC 06/58
Summary of results: Evidence of the survival of any remains of the Roman road comprised
one trench where the foundations for a metalled surface were identified. Three shallow
undated gullies were also recorded. The remaining trenches evidenced only modern truncation
and resurfacing
Monuments identified: Roman Road
Location and reference of archive: The archive is presently held at Thames Valley
Archaeological Services, Reading and will be deposited with Reading Museum in due course.
This report may be copied for bona fide research or planning purposes without the explicit permission of the
copyright holder
Report edited/checked by:
Steve Ford9 30.06.06
Steve Preston9 03.07.06
i
Thames Valley Archaeological Services Ltd, 47–49 De Beauvoir Road, Reading RG1 5NR
Tel. (0118) 926 0552; Fax (0118) 926 0553; email tvas@tvas.co.uk; website : www.tvas.co.uk
Devil’s Highway, Crowthorne, Berkshire
An Archaeological Evaluation
by Danielle Colls
Report 06/58
Introduction
This report documents the results of an archaeological field evaluation carried out at Devil’s Highway,
Crowthorne, Berkshire (SU 8457 6436 to 8586 6445) (Fig. 1). The work was commissioned by Mr J. Dymond,
for Culture and Visual Environment, Bracknell Forest Borough Council, Easthampstead House, Town Square,
Bracknell, RG12 1AQ.
In order to inform the Borough Council’s plans for conservation of this site, a brief had been prepared by
Ms Fiona McDonald, Principal Archaeologist with Berkshire Archaeology, for a programme of archaeological
trial trenching to be undertaken, to assess the potential for survival of archaeological remains below the modern
surfaces of the footpath.
This is in accordance with the Department of the Environment’s Planning Policy Guidance, Archaeology
and Planning (PPG16 1990), and Bracknell Forest Borough Council’s policies on archaeology. The field
investigation was carried out to a specification approved by Ms Fiona MacDonald, Principal Archaeologist with
Berkshire Archaeology, advisers to the Borough on archaeological matters. The fieldwork was undertaken by
Danielle Colls, Paul Sanderson and Andrew Taylor from 31st May to 16th June 2006 and the site code is DHC
06/58. The archive is presently held at Thames Valley Archaeological Services, Reading and will be deposited
with Reading Museum in due course.
Location, topography and geology
The site comprises a public right of way known as the Devil’s Highway, within woodland east of Crowthorne
and to the south of Bracknell, Berkshire (Fig. 1). The path is aligned east-west, running from the car park at SU
8457 6436 to the Sandhurst Road (A3095) at SU 8586 6445, and continuing on the same alignment towards
Silchester. Currently designated for pedestrians, the path comprises a hard surface of chippings, Tarmac and
other hard landscaping treatments, and varies in width from 1.5m to 4m. The underlying geology of the area is
mapped as London Clay (BGS 1971): a mottled orange sand loam was the underlying geology encountered in all
five trenches. The path undulates considerably and lies between 123m AOD at the highest point and 97m AOD
at its lowest point.
1
Archaeological background
The archaeological potential of the site has been highlighted in the brief prepared by Ms Fiona Macdonald. In
summary, the archaeological potential of the site is derived from its location on the course of the Roman road
from London to Silchester (Calleva Atrebatum), Margary’s route 4a (Margary 1973). There is very little
confirmed detail about the scale and construction of the road, as little investigative fieldwork has been carried
out on this section. The route is assumed to have remained in use following the end of the Roman period and
where it crosses rural areas and through Bracknell Forest, as with this section, it might be expected to have
remained relatively undisturbed.
Objectives and methodology
The purpose of the evaluation was to determine the presence/absence, extent, condition, character, quality and
date of any archaeological deposits within the area of development. Specifically, these entail:
To determine if archaeologically relevant levels have survived on the site.
To determine if archaeological deposits of any period are present.
In order to fulfil these aims, it was determined that five trenches, each 1m wide, and sufficiently long to
define the dimensions of any archaeological deposits encountered, would be excavated by hand across the width
of the road. Each trench was to be dug in two parts so as to maintain access along the road. Where features were
encountered, sufficient of these were to be hand excavated to ascertain their nature and likely dates. A complete
list of trenches giving lengths, breadths, depths and a description of sections and geology is given in Appendix 1.
Feature details are given in Appendix 2.
Results
The trenches varied in length from 6m to 8.50m, and in depth between 0.25m and 0.54m and were all aligned
roughly north-south perpendicular to the current path. Current path surfaces such as sand and chippings were
removed until archaeologically relevant levels were reached. All spoilheaps were monitored for finds including
use of a metal detector. Trench 5 showed substantial thickness of modern road surfaces, and following
discussion with Fiona McDonald the bulk of the surface in this trench was left intact.
2
Trench 1 (Fig. 4, Pl. 2)
This trench was 7.50m long in total. At the south end the stratigraphy was forest topsoil (50) (a dark grey brown
loam 0.08m thick, with very frequent tree roots) overlying very mottled brown grey sandy loam subsoil (51)
0.12m thick. This in turn overlay mottled brown and orange natural sand. Between 2.80m to 3.50m from the
south end, the surface was modern hardcore (52–4) which overlay the grey subsoil. At 1.50m, a slight linear
depression (1), 1.10m wide and infilled with compact brown grey sand (55) was recorded as a possible gully,
though its cut was unclear. No finds or dating evidence were recovered.
From 3.20m to 3.70m the subsoil layers and natural sand were truncated by a modern pipe trench for a
drain (2), which was observed but not fully exposed. This modern cut truncated lenses of grey sand infilling a
second undated shallow gully (3) and the orange sand natural. From 4.40m to 5.35m a shallow (0.28m deep)
linear depression was observed and recorded as a possible gully (4) filled with a banded green grey loam (62).
This was cut through the subsoil, which overlay the natural sand at a thickness of 0.48m at the north end of the
trench (51). Overlying the subsoil and below the topsoil (50)at the north end was a lens of orange sand (63) and
gravel 0.10m thick, which appeared to be a deposit of the same material used to surface the path. It is thought
this surface appears intermittently due to erosion but was originally a layer put down to repair the paths when the
land drain work was carried out. Some very small modern brick fragments were observed within this layer but
were not retained.
Trench 2 (Figs 5 and 6; Pl 1)
This trench was 7.95m long in total. At the south end, 0.35m of topsoil (50) overlay 0.12m of mottled grey
subsoil (66), which in turn overlay 0.10m of buried topsoil (72), in some places covered with a thin (0.05m) lens
of yellow sand (73), and comprised dark brown organic material and loam with occasional gravel and small
brick fragments. This in turn overlay mottled grey sand subsoil (68) which overlay the natural orange sand.
From 1.55m to 2.40m a modern pipe trench truncated the subsoil layers and natural orange sand. To the
north of the pipe trench, from 3.15m to 5.25m, a surface (0.05m) and an orange sand and gravel surface (0.08m)
overlay a compact dark brown sandy silt layer (67). This contained a single layer of medium sized, sub-rounded
flint cobbles that extended from 3.45m, becoming less closely packed up to 4.40m. At 5.55m to 6.50m this
single flint layer (71) reappeared, and was observed to dip down to the north. Underlying both (67) and (71) was
a compact dark grey brown sandy silt layer (69), which contained occasional small flint fragments and
occasional small modern brick fragments and blue-green glass fragments (not retained).
3
Cobble layer 71 also consistently sealed another modern pipe trench, cut through (69) and the compact
mottled grey subsoil. The cobbled surface must postdate the pipe trench, and appears to be part of the (relatively
recent) reinstatement of this section of the path.
At the north end, the topsoil overlay a modern layer of orange sand and gravel up to 0.12m which petered
out to the north and which in turn overlay mottled grey subsoil excavated to a depth of 0.24m. The orange sand
and gravel appears to be broadly contemporary with the layer to the south and at the centre of the trench, and
again is associated with the path’s repair when land drains were laid. Due to the thickness of the subsoil across
the site, and after discussion with the monitor, it was not deemed necessary to expose the natural orange sand at
the north of the trench.
Trench 3
This trench was 6.95m long overall. At the south end, topsoil 0.15m thick overlay mottled brown grey sandy
subsoil 0.17m thick. This was truncated from 1.59m to 3.31m by a broad modern pipe trench, likely to be two or
more land drains converging. The topsoil ended at c.3m, and from there the stratigraphy showed an orange-grey
mixed hardcore and gravel surface 0.08m thick (the current path surface) directly overlying a layer of medium
sized, sub-rounded flint cobbles at c.0.30m deep at 2.50m, rising in section to the surface at 3.05m. Some
cobbles appeared on the surface and it is possible that they formed a continuous layer across the path, of which a
large part has been removed by erosion. Underlying the cobbled layer was a very compact dark brown silty sand
0.40m thick, which contained occasional small and very occasional large sub-rounded flints, occasional coal and
rubber pieces. As this layer is certainly modern, the cobbled layer again postdates the land drain work. In turn,
this overlay the mottled orange natural sand.
At the north end, topsoil 0.17m thick overlay another pipe trench from 5.05m to the north end. With
agreement of the monitor the north end of this trench was not excavated down to the natural sand.
Trench 4
This trench was 5.90m long in total due to the proximity of trees. At the south end the stratigraphy was 0.18m of
topsoil overlying 0.08m purple grey sandy subsoil, which overlay the natural orange sand. At 0.80m the topsoil
petered out and the surface was mixed orange gravel or hardcore, with occasional degraded Tarmac, 0.12m thick
but becoming thinner towards the centre of the path (<0.02m thick at 3.0m). At the north end, the topsoil was
0.24m thick, directly overlying the fill of a land drain cut.
4
At 0.60m from the south to 1.40m, at 1.70m to 2.50m, and at 5.60m, three separate land drains were cut
into the natural sand. This seems to indicate that at this point along the path there was little or no road surface
when the land drain work was carried out.
Trench 5
This trench was 6.10m long overall. The stratigraphy showed 0.30m thick topsoil from the south end to 1.20m,
overlying a very compact hardcore with Tarmac patches 0.12m thick. This was removed in part and overlay a
very compact yellow hardcore and hoggin surface at least 0.15m thick. With the agreement of the monitor this
was left in situ.
From 5.10m to the north end, the stratigraphy showed topsoil at a maximum depth of 0.18m, which overlay
mottled purple grey subsoil 0.22m thick. This in turn overlay the orange sand natural.
Conclusion
From the evidence from these evaluation trenches, the remains of the Roman road are, at most, tentative. No
metalled surfaces nor flanking ditches certainly of Roman date were revealed. In most of the trenches, modern
deposits representing surfacing and resurfacing episodes directly overlay the natural geology and the presence of
modern service trenches on either side of the current path have truncated the archaeologically relevant layers.
There is no reason to cast the slightest doubt on the line of the road at this point, only the degree of its survival
Some of the deposits in Trenches 2 and 3 included layers of large cobbles, which are not a stone available
in the immediate vicinity of the site. These might be considered to represent some elements of the original road
surface. However, for Trench 3, the cobbles clearly overlay modern debris and for Trench 2, the northernmost
patch (71) partly overlay a modern pipe trench suggesting it was also a product of modern activity. Less certain
is the status of the other patch of cobbling in Trench 2 (67) which was not obviously overlying modern material
and is conceivably part of an original Roman road. Even if, as for the other patches of cobbling recorded
elsewhere in Trench 2 and in Trench 3, this activity is of modern date, it is possible that these cobbles are reused
elements of the original Roman road.
A number of shallow gullies were observed in some of the trenches. These were undated but not obviously
of modern date. They are unconvincing candidates for flanking roadside ditches and it is possible that they are
misinterpreted and are wheel ruts. It has also to be considered that Margary (1955, 79) notes that not far from
here to both the east and the west, the agger (the raised portion of the road) of this major Roman road was visible
5
(in his day) some 24 feet (c. 8m) wide and not much further east, roadside ditches were 83ft (25–26m) apart. It is
clear that the limited length of trenches dug during this evaluation, may well have only examined part of the
original road within flanking ditches if they existed at this point.
References
BGS, 1971, British Geological Survey, 1:50000, Sheet 268, Drift Edition, Keyworth
Margary, I D, 1955, Roman Roads in Britain, London
Margary, I D, 1973, Roman Roads in Britain (3rd Edition), London
PPG16, 1990, Archaeology and Planning, Dept of the Environment Planning Policy Guidance 16, HMSO
6
APPENDIX 1: Trench details
0m at south end
Trench No.
1
Length (m)
7.50
Breadth (m)
1
Depth (m)
0.54
2
7.95
1
0.48
3
6.95
1
0.42
4
5.90
1
0.25
5
6.10
1
0.30
Comment
Topsoil (0.08m thick)/hardcore(0.10m thick) onto mottled brown grey sandy
loam subsoil (0.12m-0.48m thick) onto firm mottled orange and brown sand
natural [Plate 2]
Topsoil (0.23m thick)/hardcore (0.08m thick) onto mottled brown grey
sandy loam subsoil (0.20m thick) onto firm mottled orange and brown sand
natural [Plate 1]
Topsoil/hardcore/hoggin (0.08-0.12m thick) onto mottled brown grey sandy
loam subsoil, onto firm mottled orange and brown sand natural
Topsoil/hardcore/tarmac (0.17m thick) onto firm mottled orange and brown
sand natural
Topsoil/hardcore/hoggin (0.04m thick) onto firm mottled orange and brown
sand natural
7
APPENDIX 2: Feature details
Trench
1
1
1
Cut
1
3
4
Fill (s)
55
61
62
Type
Possible gully
Possible gully
Possible gully
Date
-
8
Dating evidence
-
SITE
66000
65000
SITE
64000
63000
SU83000
84000
Devil’s Highway, Crowthorne, Berkshire, 2006
Archaeological Evaluation
Figure 1. Location of site within Crowthorne and
Berkshire.
Reproduced from Ordnance Survey Pathfinders 1189 SU86/96
at 1:25000
Ordnance Survey Licence 100025880
85000
86000
DHC06/58
Devil's Highway, Crowthorne, Berkshire 2006
N
tho
ow
Cr
rne
By
Round Hill
s
pas
Trench 5
Trench 1
Trench 2
Trench 4
Trench 3
65500
Crowthorne
Devil's Highway
65000
SU84000
85000
84500
0
85500
500m
Figure 2. Location of trenches on Devil's Highway, Crowthorne, Berkshire
DHC 06/58
Devil's Highway, Crowthorne, Berkshire 2006
N
65750
Trench 2
Trench 1
Devil's Highway
65500
84500
SU84250
0
250m
Figure 3. Location of trenches 1 and 2
DHC 06/58
Devil's Highway, Crowthorne, Berkshire 2006
N
65750
Trench 5
Trench 4
Trench 3
Devil's Highway
65500
SU84750
85000
0
85250
250m
Figure 4. Location of trenches 3, 4 and 5
DHC 06/58
Devil's Highway, Crowthorne, Berkshire, 2006
99.06m AOD
S
Trench 1
50
51
52
54
53
56
continued
below
55
1
N
50
57
50
58
63
51
61
62
59
51
3
60
4
pipe trench
2
Trench 2
105.59m
S
64
65
66
50
continued
below
67
69
68
72
73
Modern drain
N
71
Pipe trench
0
Figure 5: Sections through Trenches 1 and 2.
1m
DHC06/58
Devil's Highway, Crowthorne, Berkshire, 2006
N
Trench 2
pipe trench
(beneath)
Pipe trench
65
natural geology
1m
2m
natural geology
0
5m
71
7m
1m
Figure 6 Plan of Trench 2.
DHC06/58
Plate 1. Trench 2 looking north, Scales 1m, 0.3m and 0.1m.
Plate 2. Trench 1, looking west, vertical scale 0.3m, horizontal scale 2m
DHC06/58